// Copyright (c) 2012 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#include "content/renderer/pepper/ppb_flash_message_loop_impl.h"

#include "base/callback.h"
#include "base/message_loop/message_loop.h"
#include "base/run_loop.h"
#include "ppapi/c/pp_errors.h"
#include "third_party/WebKit/public/web/WebView.h"

using ppapi::thunk::PPB_Flash_MessageLoop_API;

namespace content {

class PPB_Flash_MessageLoop_Impl::State
    : public base::RefCounted<PPB_Flash_MessageLoop_Impl::State> {
public:
    State()
        : result_(PP_OK)
        , run_called_(false)
        , quit_called_(false)
    {
    }

    int32_t result() const { return result_; }
    void set_result(int32_t result) { result_ = result; }

    bool run_called() const { return run_called_; }
    void set_run_called() { run_called_ = true; }

    bool quit_called() const { return quit_called_; }
    void set_quit_called() { quit_called_ = true; }

    const RunFromHostProxyCallback& run_callback() const { return run_callback_; }
    void set_run_callback(const RunFromHostProxyCallback& run_callback)
    {
        run_callback_ = run_callback;
    }

private:
    friend class base::RefCounted<State>;
    virtual ~State() { }

    int32_t result_;
    bool run_called_;
    bool quit_called_;
    RunFromHostProxyCallback run_callback_;
};

PPB_Flash_MessageLoop_Impl::PPB_Flash_MessageLoop_Impl(PP_Instance instance)
    : Resource(ppapi::OBJECT_IS_IMPL, instance)
    , state_(new State())
{
}

PPB_Flash_MessageLoop_Impl::~PPB_Flash_MessageLoop_Impl()
{
    // It is a no-op if either Run() hasn't been called or Quit() has been called
    // to balance the call to Run().
    InternalQuit(PP_ERROR_ABORTED);
}

// static
PP_Resource PPB_Flash_MessageLoop_Impl::Create(PP_Instance instance)
{
    return (new PPB_Flash_MessageLoop_Impl(instance))->GetReference();
}

PPB_Flash_MessageLoop_API*
PPB_Flash_MessageLoop_Impl::AsPPB_Flash_MessageLoop_API()
{
    return this;
}

int32_t PPB_Flash_MessageLoop_Impl::Run()
{
    return InternalRun(RunFromHostProxyCallback());
}

void PPB_Flash_MessageLoop_Impl::RunFromHostProxy(
    const RunFromHostProxyCallback& callback)
{
    InternalRun(callback);
}

void PPB_Flash_MessageLoop_Impl::Quit() { InternalQuit(PP_OK); }

int32_t PPB_Flash_MessageLoop_Impl::InternalRun(
    const RunFromHostProxyCallback& callback)
{
    if (state_->run_called()) {
        if (!callback.is_null())
            callback.Run(PP_ERROR_FAILED);
        return PP_ERROR_FAILED;
    }
    state_->set_run_called();
    state_->set_run_callback(callback);

    // It is possible that the PPB_Flash_MessageLoop_Impl object has been
    // destroyed when the nested message loop exits.
    scoped_refptr<State> state_protector(state_);
    {
        base::MessageLoop::ScopedNestableTaskAllower allow(
            base::MessageLoop::current());
        blink::WebView::willEnterModalLoop();

        base::RunLoop().Run();

        blink::WebView::didExitModalLoop();
    }
    // Don't access data members of the class below.

    return state_protector->result();
}

void PPB_Flash_MessageLoop_Impl::InternalQuit(int32_t result)
{
    if (!state_->run_called() || state_->quit_called())
        return;
    state_->set_quit_called();
    state_->set_result(result);

    base::MessageLoop::current()->QuitNow();

    if (!state_->run_callback().is_null())
        state_->run_callback().Run(result);
}

} // namespace content
